Is the combination of linagliptin and allopurinol better prophylaxis against post-contrast acute kidney injury? A multicenter prospective randomized controlled study

Figures & data

Figure 1. Study flow chart.

Table 1. Demographic and baseline laboratory data of the studied patients.

Variables		Group 1 (n = 200)	Group 2 (n = 200)	Group 3 (n = 200)	Group 4 (n = 200)	p Value
Age (Years) (Mean ± SD)		48.9 ± 7.3	49 ± 7.6	48.04 ± 6.5	48.98 ± 6.9	0.47
BMI (Kg/m^2) (Mean ± SD)		25.3 ± 1.9	24.6 ± 2.7	26.4 ± 1.9	25.5 ± 1.7	<0.00001^a
Smokers (Number (%))		101 (50.5)	99 (49.5)	121 (60.5)	97 (48.5)	<0.00001^a
Hypertension (Number (%))		118 (59)	125 (62.5)	137 (68.5)	126 (63)	0.014^a
Duration of Diabetes mellitus (Years) (Mean ± SD)		7.09 ± 3.5	7.15 ± 2.2	6.4 ± 1.5	6.9 ± 1.9	0.0188^a
Laboratory data before contrast
S. Urea (mg/dL) (Mean ± SD)		66.1 ± 21.8	76.9 ± 21.04	70.3 ± 22.4	74.6 ± 22.7	0.002^a
Creatinine (mg/dL) (Mean ± SD)		2.4 ± 0.4	2.4 ± 0.4	2.4 ± 0.4	2.6 ± 0.5	0.001^a
Estimated GFR (mL/min/1.73 m²) (Mean ± SD)		28.3 ± 6.7	28.5 ± 7.9	27.7 ± 7.4	24.8 ± 6.6	0.001^a
Stage of CKD	Stage 3 CKD (Number (%))	69 (34.5)	71 (35.5)	68 (34)	40 (20)	0.0005^a
	Stage 4 CKD (Number (%))	131 (65.5)	127 (63.5)	132 (66)	156 (78)
	Stage 5 CKD (Number (%))	0 (0)	2 (1)	0 (0)	4 (2)
Urine ACR (mg/g) (Mean ± SD)		113.6 ± 29.4	116.2 ± 30.1	113.3 ± 32.9	116.5 ± 33.7	0.714
Uric acid (mg/dl) (Mean ± SD)		6.4 ± 1.2	7.7 ± 0.6	5.5 ± 1.4	7.7 ± 0.7	0.0001^a
HbA1c (Mean ± SD)		6.5 ± 0.4	6.5 ± 0.4	6.4 ± 0.4	6.4 ± 0.4	0.064
Patients with HbA1c ≤6.5% (Number (%))		129 (64.5)	101 (50.5)	118 (59)	113 (56.5)

P-value calculated by one-way ANOVA calculator.^aThe result is significant at p< .05. BMI: body mass index; SD: Standard Deviation; GFR: glomerular filtration rate using MDRD equation; ACR: albumin/creatinine ratio; HbA1c: glycated hemoglobin.

Table 2. Details of the radio-contrast provided to the patients in the study, as well as laboratory data 72 h after the contrast.

Variables	Group 1 (n = 200)	Group 2 (n = 200)	Group 3 (n = 200)	Group 4 (n = 200)	p Value
Type of imaging with contrast
Therapeutic Coronary Angiography (Number (%))	74 (37)	72 (36)	71 (35.5)	72 (36)	0.82887
Diagnostic Coronary Angiography (Number (%))	43 (21.5)	37 (18.5)	59 (29.5)	56 (28)
CT Coronary Angiography (Number (%))	21 (10.5)	25 (12.5)	26 (13)	21 (10.5)
High Resolution CT Chest (Number (%))	44 (22)	40 (20)	34 (17)	36 (18)
CT Abdomen (Number (%))	18 (9)	26 (15)	10 (5)	15 (7.5)
Type of the nonionic contrast used
Iohexol (Omnipaque) (Number (%))	105 (52.5)	91 (45.5)	95 (47.5)	97 (48.5)	0.99987
Iopromide (Ultravist) (Number (%))	95 (47.5)	109 (54.5)	105 (52.5)	103 (51.5)
Volume of contrast
Volume (mL) (Mean ± SD)	114.5 ± 30.2	115.1 ± 29	112.6 ± 31.2	111.4 ± 30.9	0.58773
75mL (Number (%))	42 (21)	33 (16.5)	53 (26.5)	55 (27.5)
100mL (Number (%))	79 (39.5)	90 (45)	70 (35)	72 (36)
150mL (Number (%))	79 (39.5)	77 (38.5)	77 (38.5)	73 (36.5)
Laboratory data 72 h after contrast injection using the Kruskal-Wallis test
Post-contrast AKI  (Number (%))	20 (10)	19 (9.5)	14 (7)	8 (4)	0.092
Percent change in urea (Mean ± SD)	−11.5 ± 10.6	−6.1 ± 4.6	−16.9 ± 10.2	−21.4 ± 11.3	<0.0001^a
Percent change in creatinine (Mean ± SD)	−1.9 ± 10.3	−0.15 ± 9.7	−2.01 ± 10.7	−6.3 ± 6.8	0.0033^a
Percent change in GFR (Mean ± SD)	3.6 ± 12	1.3 ± 11.3	3.8 ± 11.8	7.5 ± 11.01	<0.0001^a
Percent change in uric acid (Mean ± SD)	−8.03 ± 8.8	−18.4 ± 4.4	−5.3 ± 7.2	−22.5 ± 6.2	<0.0001^a
Percent change in Urine ACR (Mean ± SD)	−4.4 ± 3.4	−6.7 ± 5.6	−19.2 ± 16.2	−24.4 ± 14.4	<0.0001^a
Post contrast AKI (Chi square,confidence interval 95%)

Table

	Post contrast AKI (Number (%))	95% CI	p Value
Group 4 Contrast Induced Nephropathy (Number 8 (4%))
Group 1(Number (%))	20 (10)	0.9577% to 11.3150%	0.0188^a
Group 2(Number (%))	19 (9.5)	0.5247% to 10.7403%	0.0286^a
Group 3(Number (%))	14 (7)	−1.6255% to 7.8216%	0.1888
Group 3 Contrast Induced Nephropathy (Number 14 (7%))
Group 1(Number (%))	20 (10)	−2.5851% to 8.6714%	0.2827
Group 2(Number (%))	19 (9.5)	−3.0246% to 8.1014%	0.3641
Group 1 (n = 200) Contrast Induced Nephropathy (Number20 (10%))
Group 2(Number (%))	19 (9.5)	−5.4503% to 6.4601%	0.8663

P-value calculated by one-way ANOVA calculator. ^aThe result is significant at p< .05. SD: Standard Deviation; CT: computerized tomography; GFR: glomerular filtration rate using MDRD equation; ACR: albumin/creatinine ratio.